In the long episode, Galactica launches a suicide mission to rescue Hera from "the Colony", a Cylon base that is in a stable orbit within a black hole's accretion disk, while the rest of the fleet waits at a different point in space for their return. The issue here is, obviously, that a trip that close to a black hole will have a time dilation effect on the Galactica crew, slowing time considerably. Therefore, the fleet should have waited a lot longer than what is shown on the show.
It's weird that nobody has written about this online. I just wanted to mention it here as a reference for all those pedantic, plot-hole-seeking people out there. Also, as a question, has this point ever been officially discussed? I would love to see some excuse!